INSY 3304 FINAL EXAM 2026 ACTUAL QUESTIONS AND
ANSWERS GRADED A+
✔✔Secondary Key - ✔✔Key used strictly for data retrieval purposes
✔✔Union - ✔✔•Combines all rows from two tables, excluding duplicate rows
•Union-compatible: tables share the same number of columns, and their corresponding
columns share compatible domains
✔✔Intersection - ✔✔•Yields only the rows that appear in both tables •Tables must be
union-compatible to yield valid results
✔✔Difference - ✔✔•Yields all rows in one table that are not found in the other table
•Tables must be union-compatible to yield valid results
✔✔Product - ✔✔•Yields all possible pairs of rows from two tables
✔✔•Natural join: - ✔✔Links tables by selecting only the rows with common values in
their common attributes
✔✔Equijoin: - ✔✔Links tables on the basis of an equality condition that compares
specified columns of each table
✔✔Theta join: - ✔✔A join operator that links tables using an inequality comparison
operator (<, >, <=, >=) in the join condition.
✔✔Inner join: - ✔✔Most common type of join; includes rows in the query only when the
joined field matches records in both tables.
✔✔Outer join: - ✔✔Matched pairs are retained and unmatched values in the other table
are left null
✔✔Left outer join: - ✔✔Yields all of the rows in the first table, including those that do not
have a matching value in the second table
✔✔Right outer join: - ✔✔Yields all of the rows in the second table, including those that
do not have matching values in the first table
✔✔Divide - ✔✔•Uses one double-column table as the dividend and one single-column
table as the divisor
•Output is a single column that contains all values from the second column of the
dividend that are associated with every row in the divisor
, ✔✔Conceptual Data Model - ✔✔is a structured business view of the data required to
support business processes, record business events, and track related performance
measures.
✔✔Internal Data Model - ✔✔a representation of a database's physical storage details
-DBMS view: choose best DBMS
-internal schema: depicts a specific representation of internal model
-hardware independent, not adapted to any specific hardware platform
-software dependent
-logically independent, can change internal model without changing conceptual model
-2nd lowest level of abstraction
✔✔External Data Model - ✔✔Contains various subsets of the data items in the logical
model, also called views, tailored towards the needs of specific applications or groups of
users
-end users view
-ER diagrams: represent these external views
-external schema: will depict entities, relationships, processes, strengths
-business unit operations
-provides feedback
-security constraints
-simplification of app program development
-highest level abstraction
✔✔Physical Data Model - ✔✔is a database-specific model that represents relational
data objects (for example, tables, columns, primary and foreign keys) and their
relationships.
✔✔Entities - ✔✔Identifiers of weak entities:
•Strong identifying relationship with the parent entity •Represents a real-world object
that is existence-dependent on another real-world object •Represented in the data
model as two separate entities in a strong identifying relationship
Identifiers of composite entities:
•Each primary key combination is allowed once in M:N relationship
✔✔Attributes ( simple, composite, single valued) - ✔✔•Should be simple and single-
valued (atomic data) •Should document default values, constraints, synonyms, and
aliases •Derived attributes should be clearly identified and include source(s) •Should not
be redundant unless this is required for transaction accuracy, performance, or
maintaining a history •Nonkey attributes must be fully dependent on the PK attribute
✔✔Relationships: - ✔✔•Should clearly identify relationship participants
•Should clearly define participation, connectivity, and document cardinality
ANSWERS GRADED A+
✔✔Secondary Key - ✔✔Key used strictly for data retrieval purposes
✔✔Union - ✔✔•Combines all rows from two tables, excluding duplicate rows
•Union-compatible: tables share the same number of columns, and their corresponding
columns share compatible domains
✔✔Intersection - ✔✔•Yields only the rows that appear in both tables •Tables must be
union-compatible to yield valid results
✔✔Difference - ✔✔•Yields all rows in one table that are not found in the other table
•Tables must be union-compatible to yield valid results
✔✔Product - ✔✔•Yields all possible pairs of rows from two tables
✔✔•Natural join: - ✔✔Links tables by selecting only the rows with common values in
their common attributes
✔✔Equijoin: - ✔✔Links tables on the basis of an equality condition that compares
specified columns of each table
✔✔Theta join: - ✔✔A join operator that links tables using an inequality comparison
operator (<, >, <=, >=) in the join condition.
✔✔Inner join: - ✔✔Most common type of join; includes rows in the query only when the
joined field matches records in both tables.
✔✔Outer join: - ✔✔Matched pairs are retained and unmatched values in the other table
are left null
✔✔Left outer join: - ✔✔Yields all of the rows in the first table, including those that do not
have a matching value in the second table
✔✔Right outer join: - ✔✔Yields all of the rows in the second table, including those that
do not have matching values in the first table
✔✔Divide - ✔✔•Uses one double-column table as the dividend and one single-column
table as the divisor
•Output is a single column that contains all values from the second column of the
dividend that are associated with every row in the divisor
, ✔✔Conceptual Data Model - ✔✔is a structured business view of the data required to
support business processes, record business events, and track related performance
measures.
✔✔Internal Data Model - ✔✔a representation of a database's physical storage details
-DBMS view: choose best DBMS
-internal schema: depicts a specific representation of internal model
-hardware independent, not adapted to any specific hardware platform
-software dependent
-logically independent, can change internal model without changing conceptual model
-2nd lowest level of abstraction
✔✔External Data Model - ✔✔Contains various subsets of the data items in the logical
model, also called views, tailored towards the needs of specific applications or groups of
users
-end users view
-ER diagrams: represent these external views
-external schema: will depict entities, relationships, processes, strengths
-business unit operations
-provides feedback
-security constraints
-simplification of app program development
-highest level abstraction
✔✔Physical Data Model - ✔✔is a database-specific model that represents relational
data objects (for example, tables, columns, primary and foreign keys) and their
relationships.
✔✔Entities - ✔✔Identifiers of weak entities:
•Strong identifying relationship with the parent entity •Represents a real-world object
that is existence-dependent on another real-world object •Represented in the data
model as two separate entities in a strong identifying relationship
Identifiers of composite entities:
•Each primary key combination is allowed once in M:N relationship
✔✔Attributes ( simple, composite, single valued) - ✔✔•Should be simple and single-
valued (atomic data) •Should document default values, constraints, synonyms, and
aliases •Derived attributes should be clearly identified and include source(s) •Should not
be redundant unless this is required for transaction accuracy, performance, or
maintaining a history •Nonkey attributes must be fully dependent on the PK attribute
✔✔Relationships: - ✔✔•Should clearly identify relationship participants
•Should clearly define participation, connectivity, and document cardinality
